分页处理封装+分页查询题目列表

文章目录

- 1.sun-club-common封装分页
- - - 1.com/sunxiansheng/subject/common/eneity/PageInfo.java
    - 2.com/sunxiansheng/subject/common/eneity/PageResult.java
- 2.sun-club-application-controller
- - - 1.SubjectInfoDTO.java 继承PageInfo并新增字段
    - 2.SubjectController.java
- 3.sun-club-domain
- - - 1.SubjectInfoBO.java 继承PageInfo并增加字段
    - 2.SubjectInfoDomainService.java
    - 3.SubjectInfoDomainServiceImpl.java
- 4.sun-club-infra
- - - 1.SubjectInfoService.java
    - 2.SubjectInfoServiceImpl.java
    - 3.SubjectInfoDao.java
    - 4.SubjectInfoDao.xml
    - 5.测试

1.sun-club-common封装分页

1.com/sunxiansheng/subject/common/eneity/PageInfo.java

package com.sunxiansheng.subject.common.eneity;

/**
 * Description: 分页请求的入参
 * @Author sun
 * @Create 2024/5/28 16:25
 * @Version 1.0
 */
public class PageInfo {

    private Integer pageNo = 1;

    private Integer pageSize = 20;

    public Integer getPageNo() {
        if (pageNo == null || pageNo < 1) {
            return 1;
        }
        return pageNo;
    }

    public Integer getPageSize() {
        if (pageSize == null || pageSize < 1 || pageSize > Integer.MAX_VALUE) {
            return 20;
        }
        return pageSize;
    }

    public void setPageNo(Integer pageNo) {
        this.pageNo = pageNo;
    }

    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }
}

2.com/sunxiansheng/subject/common/eneity/PageResult.java

package com.sunxiansheng.subject.common.eneity;

import java.util.Collections;
import java.util.List;

/**
 * Description: 分页返回的实体
 * @Author sun
 * @Create 2024/5/28 16:36
 * @Version 1.1
 */
public class PageResult<T> {

    // 当前页码，默认为1
    private Integer pageNo = 1;

    // 每页显示的记录数，默认为20
    private Integer pageSize = 20;

    // 总记录条数
    private Integer total = 0;

    // 总页数
    private Integer totalPages = 0;

    // 当前页的记录列表
    private List<T> result = Collections.emptyList();

    // 表示当前页是从数据库的第几条记录开始，下标从1开始
    private Integer start = 1;

    // 表示当前页是从数据库的第几条记录结束，下标从1开始
    private Integer end = 0;

    // 设置当前页码，并重新计算起始和结束位置
    public void setPageNo(Integer pageNo) {
        this.pageNo = pageNo;
        calculateStartAndEnd();
    }

    // 设置每页记录数，并重新计算起始和结束位置
    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
        calculateStartAndEnd();
    }

    // 设置当前页的记录列表
    public void setRecords(List<T> result) {
        this.result = result;
    }

    // 设置总记录条数，并重新计算总页数和起始结束位置
    public void setTotal(Integer total) {
        this.total = total;
        calculateTotalPages();
        calculateStartAndEnd();
    }

    // 计算总页数
    private void calculateTotalPages() {
        if (this.pageSize > 0) {
            this.totalPages = (this.total / this.pageSize) + (this.total % this.pageSize == 0 ? 0 : 1);
        } else {
            this.totalPages = 0;
        }
    }

    // 计算起始和结束位置
    private void calculateStartAndEnd() {
        if (this.pageSize > 0) {
            this.start = (this.pageNo - 1) * this.pageSize + 1;
            this.end = Math.min(this.pageNo * this.pageSize, this.total);
        } else {
            this.start = 1;
            this.end = this.total;
        }
    }

    // 获取数据库查询的起始位置（从0开始）
    public Integer getDBStart() {
        return start - 1;
    }

    // 获取每页记录数
    public Integer getPageSize() {
        return pageSize;
    }

    // 可选的 Getters 和 Setters
    public Integer getPageNo() {
        return pageNo;
    }

    public Integer getTotal() {
        return total;
    }

    public Integer getTotalPages() {
        return totalPages;
    }

    public List<T> getResult() {
        return result;
    }

    public Integer getEnd() {
        return end;
    }
    
    public Integer getStart() {
        return start;
    }
}

2.sun-club-application-controller

1.SubjectInfoDTO.java 继承PageInfo并新增字段

package com.sunxiansheng.subject.application.dto;

import com.sunxiansheng.subject.common.eneity.PageInfo;
import lombok.Data;

import java.io.Serializable;
import java.util.List;

/**
 * 题目信息表(SubjectInfo)实体类
 *
 * @author makejava
 * @since 2024-05-26 17:26:43
 */
@Data
public class SubjectInfoDTO extends PageInfo implements Serializable {
    private static final long serialVersionUID = -99877276843752542L;

    /**
     * 主键
     */
    private Long id;
    /**
     * 题目名称
     */
    private String subjectName;
    /**
     * 题目难度
     */
    private Integer subjectDifficult;
    /**
     * 题目类型 1单选 2多选 3判断 4简答
     */
    private Integer subjectType;
    /**
     * 题目分数
     */
    private Integer subjectScore;
    /**
     * 题目解析
     */
    private String subjectParse;

    /**
     * 题目答案
     */
    private String subjectAnswer;

    /**
     * 分类id
     */
    private List<Long> categoryIds;

    /**
     * 标签id
     */
    private List<Long> labelIds;

    /**
     * 答案选项
     */
    private List<SubjectAnswerDTO> optionList;

    /**
     * 分类id
     */
    private Long categoryId;

    /**
     * 标签id
     */
    private Long labelId;
}

2.SubjectController.java

/**
 * 分页查询题目列表
 * @param subjectInfoDTO
 * @return
 */
@PostMapping("/getSubjectPage")
public Result<PageResult<SubjectInfoDTO>> getSubjectPage(@RequestBody SubjectInfoDTO subjectInfoDTO) {
    try {
        // 打印日志
        if (log.isInfoEnabled()) {
            log.info("SubjectController getSubjectPage SubjectInfoDTO, subjectInfoDTO:{}", JSON.toJSONString(subjectInfoDTO));
        }

        // 参数校验
        Preconditions.checkNotNull(subjectInfoDTO.getCategoryId(), "分类id不能为空");
        Preconditions.checkNotNull(subjectInfoDTO.getLabelId(), "标签id不能为空");

        // 转换DTO为BO
        SubjectInfoBO subjectInfoBO = SubjectInfoDTOConverter.INSTANCE.convertDTO2BO(subjectInfoDTO);
        // 由于mapstruct在转换的时候不会考虑继承的字段，所以需要手动转换
        subjectInfoBO.setPageNo(subjectInfoDTO.getPageNo());
        subjectInfoBO.setPageSize(subjectInfoDTO.getPageSize());

        // 分页查询题目列表
        PageResult<SubjectInfoBO> boPageResult = subjectInfoDomainService.getSubjectPage(subjectInfoBO);

        return Result.ok(boPageResult);
    } catch (Exception e) {
        log.error("SubjectController getSubjectPage error, subjectInfoDTO:{}", e.getMessage(), e);
        return Result.fail("分页查询题目列表失败");
    }
}

3.sun-club-domain

1.SubjectInfoBO.java 继承PageInfo并增加字段

package com.sunxiansheng.subject.domain.entity;

import com.sunxiansheng.subject.common.eneity.PageInfo;
import lombok.Data;

import java.io.Serializable;
import java.util.List;

/**
 * 题目信息表(SubjectInfo)实体类
 *
 * @author makejava
 * @since 2024-05-26 17:26:43
 */
@Data
public class SubjectInfoBO extends PageInfo implements Serializable {
    private static final long serialVersionUID = 1L;

    /**
     * 主键
     */
    private Long id;
    /**
     * 题目名称
     */
    private String subjectName;
    /**
     * 题目难度
     */
    private Integer subjectDifficult;
    /**
     * 题目类型 1单选 2多选 3判断 4简答
     */
    private Integer subjectType;
    /**
     * 题目分数
     */
    private Integer subjectScore;
    /**
     * 题目解析
     */
    private String subjectParse;

    /**
     * 题目答案
     */
    private String subjectAnswer;

    /**
     * 分类id
     */
    private List<Long> categoryIds;

    /**
     * 标签id
     */
    private List<Long> labelIds;

    /**
     * 答案选项
     */
    private List<SubjectAnswerBO> optionList;

    /**
     * 分类id
     */
    private Long categoryId;

    /**
     * 标签id
     */
    private Long labelId;
}

2.SubjectInfoDomainService.java

/**
 * 分页查询题目列表
 * @param subjectInfoBO
 * @return
 */
PageResult<SubjectInfoBO> getSubjectPage(SubjectInfoBO subjectInfoBO);

3.SubjectInfoDomainServiceImpl.java

@Override
public PageResult<SubjectInfoBO> getSubjectPage(SubjectInfoBO subjectInfoBO) {
    // 打印日志
    if (log.isInfoEnabled()) {
        log.info("SubjectInfoDomainServiceImpl getSubjectPage SubjectInfoBO, SubjectInfoBO:{}", subjectInfoBO);
    }
    // 创建一个要返回的对象
    PageResult<SubjectInfoBO> pageResult = new PageResult<>();
    pageResult.setPageNo(subjectInfoBO.getPageNo());
    pageResult.setPageSize(subjectInfoBO.getPageSize());
    // 将bo转换为eneity
    SubjectInfo subjectInfo = SubjectInfoConverter.INSTANCE.convertBoToSubjectInfo(subjectInfoBO);
    // 根据条件查询记录条数
    int count = subjectInfoService.countByCondition(subjectInfo, subjectInfoBO.getCategoryId(), subjectInfoBO.getLabelId());
    // 进行判断
    if (count == 0) {
        return pageResult;
    }
    // 设置总记录条数
    pageResult.setTotal(count);
    // 进行分页查询
    List<SubjectInfo> subjectInfoList = subjectInfoService.queryPage(subjectInfo, subjectInfoBO.getCategoryId(), subjectInfoBO.getLabelId(),
            pageResult.getDBStart(), pageResult.getPageSize());
    // 将entity转换为bo
    List<SubjectInfoBO> subjectInfoBOS = SubjectInfoConverter.INSTANCE.convertSubjectInfoToBo(subjectInfoList);
    // 设置所有的记录
    pageResult.setRecords(subjectInfoBOS);
    return pageResult;
}

4.sun-club-infra

1.SubjectInfoService.java

/**
 * 根据条件返回题目的记录条数
 * @param subjectInfo
 * @param categoryId
 * @param labelId
 * @return
 */
int countByCondition(SubjectInfo subjectInfo, Long categoryId, Long labelId);

/**
 * 根据条件返回题目的记录
 * @param subjectInfo
 * @param categoryId
 * @param labelId
 * @param start
 * @param pageSize
 * @return
 */
List<SubjectInfo> queryPage(SubjectInfo subjectInfo, Long categoryId, Long labelId, Integer start, Integer pageSize);

2.SubjectInfoServiceImpl.java

    /**
     * 根据条件查询出题目的数量
     *
     * @param subjectInfo
     * @param categoryId
     * @param labelId
     * @return
     */
    @Override
    public int countByCondition(SubjectInfo subjectInfo, Long categoryId, Long labelId) {
        return subjectInfoDao.countByCondition(subjectInfo, categoryId, labelId);
    }

    /**
     * 根据条件返回题目的记录
     * @param subjectInfo
     * @param categoryId
     * @param labelId
     * @param start
     * @param pageSize
     * @return
     */
    @Override
    public List<SubjectInfo> queryPage(SubjectInfo subjectInfo, Long categoryId, Long labelId, Integer start, Integer pageSize) {
        return subjectInfoDao.queryPage(subjectInfo, categoryId, labelId, start, pageSize);
    }

3.SubjectInfoDao.java

/**
 * 根据条件返回题目的记录条数
 * @param subjectInfo
 * @param categoryId
 * @param labelId
 * @return
 */
int countByCondition(@Param("subjectInfo") SubjectInfo subjectInfo,
                     @Param("categoryId") Long categoryId,
                     @Param("labelId") Long labelId);

/**
 * 根据条件返回题目的记录
 * @param subjectInfo
 * @param categoryId
 * @param labelId
 * @param start
 * @param pageSize
 * @return
 */
List<SubjectInfo> queryPage(@Param("subjectInfo") SubjectInfo subjectInfo,
                            @Param("categoryId") Long categoryId,
                            @Param("labelId") Long labelId,
                            @Param("start") Integer start,
                            @Param("pageSize") Integer pageSize);

4.SubjectInfoDao.xml

<!--根据条件统计总行数-->
<select id="countByCondition" resultType="java.lang.Integer">
    select count(1)
    from subject_info a,
         subject_mapping b
    where a.id = b.subject_id
      and a.is_deleted = 0
      and b.is_deleted = 0
      and a.subject_difficult = #{subjectInfo.subjectDifficult}
      and b.category_id = #{categoryId}
      and b.label_id = #{labelId}
</select>

<!--根据条件分页查询-->
<select id="queryPage" resultMap="SubjectInfoMap">
    select a.id,
           a.subject_name,
           a.subject_difficult,
           a.settle_name,
           a.subject_type,
           a.subject_score,
           a.subject_parse,
           a.created_by,
           a.created_time,
           a.update_by,
           a.update_time,
           a.is_deleted
    from subject_info a,
         subject_mapping b
    where a.id = b.subject_id
      and a.is_deleted = 0
      and b.is_deleted = 0
      and a.subject_difficult = #{subjectInfo.subjectDifficult}
      and b.category_id = #{categoryId}
      and b.label_id = #{labelId}
    limit #{start}, #{pageSize}
</select>